The present invention relates to an apparatus and method for removing mud and effluents from a drilling operation and more specifically to providing wide-bore adjustable pipes for the carriage of mud from a mobile drilling rig.
Modern slant-well drilling techniques allow for efficient boring to hydrocarbon reservoirs from a relatively centralized location on the surface. This approach permits a single drill site to operate multiple boreholes thereby re-using much of the equipment and other resources that otherwise would be committed to a single borehole. This technique of drilling boreholes from a central location is possible through the use of slant and directional drilling. Accordingly, the central base of operations contrasts to the drilling methods employed decades ago to drill once per section of land straight down from the rig.
FIG. 1A is a top view of rig, mud-pipe and mud tank configuration according to the prior art. Drilling rig 101 may initially be positioned above borehole 121 during drilling and other operations that service the borehole. The drilling rig or, for brevity, ‘rig’, is the rotary table, top drive and any equipment that supports these devices so that a drill string may be lowered into a borehole. Drilling boreholes requires the use of effluents, commonly referred to as drilling mud or mud. The drilling mud removes broken rock and other materials that are carved away by the drill bit in order to permit further boring into the formation. The mud and other earthen material are carried up the bore hole and directed to mud pipe 107, which carries, usually by operation of gravity, the mix to a shaker manifold 103 which may further directs the mud shale shakers (not shown) and eventually to mud tank 105.
Mud tank 105 is usually affixed to the ground. Even when not attached to the ground, mud tanks are weighted down even when only fractionally filled with mud. Accordingly, mud tanks are not moved without a great deal of effort.
One way the industry has contended with the relative inflexibility of a mud tank is to employ a manifold with nipples, for example, nipples 131-135. The nipples provide a stationary point of attachment for mud pipe 107. When additional boreholes are needed, such as, for example, boreholes 122-125, only rig 101 need be moved to provide access to the additional boreholes. Accordingly, shaker manifold 103 is placed parallel to a line containing the existing or proposed boreholes, such as, for example, boreholes 122-125. The nipples are arranged to correspond to a point directly across from each additional borehole. Thus, when the rig 101 is located over, for example, borehole 122, mud pipe 107 can be installed at the rig's new location to carry the mud a distance to the shaker manifold 103 that is identical to the distance the mud traveled at the mud pipe's 107 former location. Accordingly, mud takes a relatively direct route from borehole 122 to nipple 132.
FIG. 1B is a top view of a rig 101, mud-pipe 107 and mud tank 105 configuration according to the prior art in position two. As can be seen, FIG. 1B shows the rig 101, in simplified form, present over borehole 122 having mud pipe 107 connecting the borehole to nipple 132.
Oilfield operators typically perform the following process to complete a borehole and prepare to drill a subsequent borehole. First, a crew detaches mud pipe 107 at one end, and then detaches the mud pipe at the other second end. Second, the crew moves the mud pipe to a safe location. Third, the crew moves the rig's to a new location. Fourth, the crew moves the mud pipe into position at a new nipple. Fifth, the crew reattaches the mud pipe at the new location so mud can flow from rig to the mud tank. These steps can add a few hours to the downtime that a rig is not actually boring a borehole, sometimes causing members of the drilling crew to be idle during that time. Moreover, this process can be repeated many times over—once for each additional borehole desired at a site.
Accordingly, a faster process is desired.